Not exactly - you can create dummy MA and configure it as password synchronization target, then use this agent password extension to write some log file. For such MA you can use SQL MA to not create something specific with custom password synch extension
BTW: PCNS and Synch engine which receives PCNS calls has event logging mechanism built-in. Why not gather events from event log?
Tomek Onyszko, memberOf Predica FIM Team (http://www.predica.pl), IdAM knowledge provider @ http://blog.predica.pl